Before, it was a chore to be got through so I could go home, feel good about myself and eat lots of Hula Hoops. Now I find, to my astonishment, it's the high point of my week. I practise moves in the living-room before I go to bed. I no longer pretend I'm struggling more than I actually am in order to slack off during press-ups. I've bought one of those squeezy sports water bottles. (OK, it's a Lion King one, but it still shows commitment.)
And to my further astonishment, I'm feeling pretty damn fit. At football practice yesterday I did three laps of the pitch as a warm-up and didn't feel like my chest was going to explode. I know it's only a five-a-side pitch, but even so.
If you've been thinking about taking up some form of physical exercise, please consider karate. You'll get so much more out of it, physically, mentally - spiritually? - than you would from a boring old gym. And it might even come in useful; has anyone ever scared off a mugger by doing step aerobics at them?